I've just been pondering such a service, as the result of a friend of mine, being moved to an assisted living facility. He has no email there, and wouldn't be able to use it if he did. I would love to send him quick updates on my life and my kids, but, while I could spare him five minutes to dash off an email and attach some photos to it, the task of printing the photos on a color printer, finding his address, etc., usually gets the task procrastinated, sometimes for weeks, in that "I'll do it tomorrow" procrastination dance.<p>My thoughts on this line were as follows.<p>1) It needs to allow photos. They can be an extra charge of course, but I would want to send photos.<p>2) There's a ton of paper handling equipment out there. If you invested about $20K, maybe 10K if you bought used, I would think you could get a solution that was 100% automated. It printed, stapled, folded, printed the envelope, and stuffed the contents. A service with such an automated capability, that showed pictures of their equipment on their website so I knew it was real, would definitely be reassuring from a privacy standpoint, as well as a reliability standpoint.<p>3) As for API, my thought was to make the whole thing, just email. Parse incoming emails to confirm the sender is an account holder. Parse the email for the markup headers that you define to designate recipient address. If they don't exist, fire off a reply email to the same address, telling them they messed up and didn't mark up their submission properly. Done. No visiting your website at all, after I set up my account.<p>3a) I would also suggest a way for me to assign frequently used snail mail addresses as part of an email address. For example, say you assign me the email address QWERTY@mailservice.com. Whenever I mail to that address, you know it's my account, and send the contents of the appropriately marked up email to the recipients. OK, fine. But now, allow me to assign sub-addresses. So, for example, if I email QWERTY.terry@mailservice.com, and I've already defined the address of terry, now I don't have to mark up my email at all. I just put QWERTY.terry@mailservice.com into my email address book, and my friend Terry is the same as contacting anybody else with email. With such a system, mailing somebody and emailing somebody take exactly the same steps on my part. In fact, I can even CC them on an email I send to somebody else.